Hi Don, I think it's a big mistake not to use metal (aluminum or steel)
for your frame. From a longivity stand point, non conductive material would
have a tough time withstanding the constant movement without breaking
sometime. I say put up an H frame with 2 horizontals. Now, that is strong!
That's what we use on Mt. Greylock (W2SZ/1) in the contests and have no
trouble even in very windy conditions. Elev 3491'
As far as interaction I doubt if you will see any because of the distances
involved and the fact that the antennas would be mounted on vertical
supports. My 2 cents
Good luck and 73, Don K1DH (six meter op: W2SZ)
>From: "Donald M. Ross" <dross@sirinet.net>
>To: "VHF Reflector" <vhf@w6yx.stanford.edu>, "VHF Contest Reflector"
><vhfcontesting@contesting.com>, "RMVHF Society" <rmvhf@mailman.qth.net>
>Subject: [VHFcontesting] Stacking Frame Questions
To: <vhfcontesting@contesting.com>
>Date: Mon, 29 Jul 2002 10:42:53 -0500
>
>One for the guru's.
>
>I am finally getting around to building up the VHF/UHF stack on the tower
>and have some questions about building the frame for the antennas.
>Intellectually, I know that I want to build something non-metallic so that
>it doesn't affect the radiation patterns, but I am stumped as to how to do
>this.
>
>The plan is to stack two M2 2M18XXX on the left side of the array and an M2
>220-7WL, an M2 432-13WLA, and an M2 23CM23EZ (to be replaced eventually
>with
>a 35 element one) on the right hand side. I've sent an e-mail to M2 about
>stacking distances, but since the horizontal stacking distance of the
>18XXX's is 14' I think that I'm looking at something no longer/wider than
>16'. The array needs to be strong enough to support the antennas and
>handle
>moderate winds since it will be on a hazer and lowered when I am traveling
>or the winds get to be aggressive.
>
>I've seen ads for solid fiberglass rods, but only in maximum lengths of 8'.
>Is there a way to join them together or does someone know of a source for
>longer ones?
>
>I'd really like to hear of your successes (and failures so that I don't
>take
>the same road) and opinions.
>
>I'd like to have it up for September, but am probably looking more
>logically
>on January before the array is fully tested and in the air.
>
>Don Ross, NL CO/EM04
>
>
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